The research team, led by Dr. Jeong Gon Son from the Soft Hybrid Materials Research Center at the Korea Institute of Science and Technology (KIST; President: Seok-Jin Yoon), announced that they had developed a lithium battery wherein all of the materials, including the anode, cathode, current collector, electrolytes, and encapsulant, are stretchable and printable.
The lithium battery developed by the team possesses high capacity and free-form characteristics suitable for mechanical deformation.
Owing to the rapidly increasing demand for high-performance wearable devices—such as smart bands, implantable electronic devices such as pace-makers, and soft wearable devices for use in the realistic metaverse—the development of a battery that is soft and stretchable like the human skin and organs has been attracting interest.
To enhance stretchability, the research team avoided using materials utilized in other studies that were unnecessary for energy storage, such as rubber. Then, a new soft and stretchable organic gel material was developed and applied based on the existing binder material. This material firmly holds the active electrode materials in place and facilitates the transfer of ions. In addition, a conductive ink was fabricated using a material with excellent stretchability and gas barrier properties to serve as as a current collector material that transfers electrons and an encapsulant that can function stably even at a high voltage and in various deformed states without swelling due to electrolyte absorption.

The battery developed by the team is also able to incorporate existing lithium-ion battery materials, as they exhibit excellent energy storage density (~2.8 mWh/cm2) of a level similar to that of commercially available hard lithium-ion batteries at a driving voltage of 3.3 V or higher. All of the constituent components of the team’s stretchable lithium-ion battery possess the mechanical stability to maintain their performance even after repeated pulling of the battery 1,000 or more times, a high stretchability of 50% or above, and long-term stability in air.

Dr. Son at KIST stated that his team has developed a stretchable lithium-ion battery technology that provides both structural freedom as a result of the battery’s free-form configuration allowing for it to be printed on materials such as fabrics, and material freedom due to being able to use existing lithium-ion battery materials, in addition to stretch stability that allows for high energy density and mechanical deformation. He also stated that the stretchable energy storage system developed by his team is expected to be applicable to the development of various wearable or body-attachable devices.

More information: Soo Yeong Hong et al, Intrinsically Stretchable and Printable Lithium-Ion Battery for Free-Form Configuration, ACS Nano (2022). DOI: 10.1021/acsnano.1c08405